Civilization One: The World is Not as You Thought it Was by Christopher Knight, Alan Butler Page B
Authors: Christopher Knight, Alan Butler
Tags: Civilization One
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13th centuries the Champagne fairs, held regularly in specific towns and cities in the region, positively encouraged merchants from all over Europe and beyond to exchange goods. These were huge trade fairs (rather than markets for consumers) that were held under the authority of the dukes of Champagne and new, or apparently new weights and measures appeared at this time. Many British people will be surprised to learn that their much-loved pound and ounce made their first known appearance as French units at these fairs.
It is certain that both units of length and weight were created deliberately to serve the fairs in an attempt to offer common measures that everyone could understand and use without confusion. With the gradual demise in the importance of the fairs and with so much fighting taking place between the emerging nation states of the region, units of length and weight often became a strictly local matter, though frequently with underlying aspects of the old Roman system. Britain struggled but somehow managed with a seemingly incomprehensible muddle of different units, though the country we now know as France was in an even worse state.
Prior to the early 14th century, France was a series of different states which had not been united since Roman times. These were only welded together again as a result of conquests and dynastic unions resulting in virtual chaos, with a wealth of different length, weight and volume unit names and sizes existing simultaneously across the new country. Matters were made even more complicated by the fact that some units retained a common name in different regions even though they differed in size. The chaos continued until some new data on the circumference of the Earth was published in 1670 by Jean Picard, a priest and an astronomer living in La Flèche. Picard accurately assessed the polar circumference of the Earth using the distance from Sourdon near Amiens, to Malvoisine south of Paris, as his test area. This gave another priest an inspired thought.
A new system
Father Gabriel Mouton of St Paul’s Church in Lyon put forward the suggestion that France should design a completely original set of decimalized weights and measures based upon an agreed fraction of the length of one minute of arc of the newly-measured polar circumference of the planet. The idea immediately caught the imagination of leading thinkers, but Picard did not agree with Mouton’s suggestion for the means of devising a new linear measure. Instead, together with astronomer Ole Römer (a distinguished scientist from Copenhagen who spent long periods in France and Germany), Picard proposed that the new unit of linear length upon which everything else could be based, should be precisely the length of a pendulum with a beat of one second of time.
The ‘seconds pendulum’
The concept of a ‘seconds pendulum’ had been first identified by Galileo earlier in the same century when he became the first recorded European to actively experiment with pendulums, though it was left to the Englishman Isaac Newton (1643–1727) to later establish correct dimensions for the seconds pendulum. The device had a particular fascination for Newton, who experimented extensively in all matters pertaining to gravity. Newton had calculated that a freely-swinging pendulum, at a location of 45 degrees latitude, with a beat of exactly 1 second, would measure 39.14912 inches in length which was correct to within one twenty-five thousandth of a second. (While this is all of great historical interest we demonstrated in the last chapter that the Sumerians had achieved all these objectives some 3,500 years earlier.)
It was known by the time of Picard and Römer that gravity did not act equally on all parts of the planet because the Earth is an oblique spheroid rather than a perfect sphere. The astronomers seem to have favoured basing the new linear unit on the seconds pendulum measured at Paris, though Newton’s 45-degree latitude was also
It is certain that both units of length and weight were created deliberately to serve the fairs in an attempt to offer common measures that everyone could understand and use without confusion. With the gradual demise in the importance of the fairs and with so much fighting taking place between the emerging nation states of the region, units of length and weight often became a strictly local matter, though frequently with underlying aspects of the old Roman system. Britain struggled but somehow managed with a seemingly incomprehensible muddle of different units, though the country we now know as France was in an even worse state.
Prior to the early 14th century, France was a series of different states which had not been united since Roman times. These were only welded together again as a result of conquests and dynastic unions resulting in virtual chaos, with a wealth of different length, weight and volume unit names and sizes existing simultaneously across the new country. Matters were made even more complicated by the fact that some units retained a common name in different regions even though they differed in size. The chaos continued until some new data on the circumference of the Earth was published in 1670 by Jean Picard, a priest and an astronomer living in La Flèche. Picard accurately assessed the polar circumference of the Earth using the distance from Sourdon near Amiens, to Malvoisine south of Paris, as his test area. This gave another priest an inspired thought.
A new system
Father Gabriel Mouton of St Paul’s Church in Lyon put forward the suggestion that France should design a completely original set of decimalized weights and measures based upon an agreed fraction of the length of one minute of arc of the newly-measured polar circumference of the planet. The idea immediately caught the imagination of leading thinkers, but Picard did not agree with Mouton’s suggestion for the means of devising a new linear measure. Instead, together with astronomer Ole Römer (a distinguished scientist from Copenhagen who spent long periods in France and Germany), Picard proposed that the new unit of linear length upon which everything else could be based, should be precisely the length of a pendulum with a beat of one second of time.
The ‘seconds pendulum’
The concept of a ‘seconds pendulum’ had been first identified by Galileo earlier in the same century when he became the first recorded European to actively experiment with pendulums, though it was left to the Englishman Isaac Newton (1643–1727) to later establish correct dimensions for the seconds pendulum. The device had a particular fascination for Newton, who experimented extensively in all matters pertaining to gravity. Newton had calculated that a freely-swinging pendulum, at a location of 45 degrees latitude, with a beat of exactly 1 second, would measure 39.14912 inches in length which was correct to within one twenty-five thousandth of a second. (While this is all of great historical interest we demonstrated in the last chapter that the Sumerians had achieved all these objectives some 3,500 years earlier.)
It was known by the time of Picard and Römer that gravity did not act equally on all parts of the planet because the Earth is an oblique spheroid rather than a perfect sphere. The astronomers seem to have favoured basing the new linear unit on the seconds pendulum measured at Paris, though Newton’s 45-degree latitude was also
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